year = input('请输入年：')
month = int(input('请输入月：'))
day = int(input('请输入日：'))
hour = int(input('请输入时：'))
minute = int(input('请输入分：'))
second = int(input('请输入秒：'))

country = input('1.中国;2.美国;3.英国;4.德国;'
                '5.俄罗斯;6.澳大利亚;7.法国;8.加拿大;请输入数字选择国家：')
time = ''
if country == '1':
    # 中国yyyy年MM月dd日 HH:mm:ss
    time = f'{year}年{month:02d}月{day:02d}日 {hour:02d}:{minute:02d}:{second:02d}'
elif country == '2':
    time = f'{month:02d}/{day:02d}/{year} {hour:02d}:{minute:02d}:{second:02d}'
# ...
print(time)